Context: The Food and Agriculture Organization has estimated that every year considerable losses of the food crops occur due to plant diseases. Although fungicides are extensively used for management of plant diseases, they are expensive and hazardous to the environment and human health. Alternatively, biological control is the safe way to overcome the effects of plant diseases and to sustain agriculture. Since Monarda citriodora Cerv. ex Lag. (Lamiaceae/Labiatae) is known for its antifungal properties, it was chosen for the study. Objective: The isolation of endophytic fungi from M. citriodora and assessing their biocontrol potential. Material and methods: The isolated endophytes were characterized using ITS-5.8 S rDNA sequencing. Their biocontrol potential was assessed using different antagonistic assays against major plant pathogens. Results: Twenty-eight endophytes representing 11 genera were isolated, of which, around 82% endophytes showed biocontrol potential against plant pathogens. MC-2 L (Fusarium oxysporum), MC-14 F (F. oxysporum), MC-22 F (F. oxysporum) and MC-25 F (F. redolens) displayed significant antagonistic activity against all the tested pathogens. Interestingly, MC-10 L (Muscodor yucatanensis) completely inhibited the growth of Sclerotinia sp., Colletotrichum capsici, Aspergillus flavus and A. fumigatus in dual culture assay, whereas MC-8 L (A. oryzae) and MC-9 L (Penicillium commune) completely inhibited the growth of the Sclerotinia sp. in fumigation assay. Conclusions: Endophytes MC-2 L, MC-14 F, MC-22 F and MC-25 F could effectively be used to control broad range of phytopathogens, while MC-10 L, MC-8 L and MC-9 L could be used to control specific pathogens. Secondly, endophytes showing varying degrees of antagonism in different assays represented the chemo-diversity not only as promising biocontrol agents but also as a resource of defensive and bioactive metabolites.

Present study focuses on diversity and distribution analysis of endophytic fungi associated with different tissues of the Monarda citriodora Cerv. ex Lag. (Lamiaceae/Labiatae). Anticancer and antimicrobial potential of isolated endophytes have also been investigated. A total of twenty eight fungal endophytes belonging to 11 different genera were isolated from this plant. All the endophytic fungi belonged to the Ascomycota phylum. The leaves were immensely rich in fungal species, while roots showed the highest tissue specific fungal dominance. Out of 28 fungal species, 72% endophytic extracts were found cytotoxic against one or more human cancer cell lines. The most prominent anticancer activity (IC50 value <10 μg/mL) was shown by MC-14 L (Fusarium oxysporum), MC-14 F (F. oxysporum), MC-18 L (Aspergillus fumigatus), MC-24 L (Cladosporium tenuissimum), MC-25 L (Fusarium sp.), MC-26 F (F. oxysporum) extracts. 75% of the extracts showed antimicrobial activities in agar disc-diffusion assay and 27% in the tube dilution method (MIC <100 μg/mL) respectively against the tested pathogens. Extracts of MC-14 L (F. oxysporum) and MC-18 L (A. fumigatus) displayed broad spectrum antimicrobial activity. These results indicated that M. citriodora harbors a rich fungal endophytic community with anticancer and antimicrobial activities. The isolated endophyte MC-24 L (C. tenuissimum) has the potential to be a source of novel cytotoxic/antimicrobial compounds. This is the first report of diversity of fungal endophytes isolated from M. citriodora.

Endophytes, which reside in plant tissues, have the potential to produce novel metabolites with immense benefits for health industry. Cytotoxic and antimicrobial activities of endophytic fungi isolated from Bacopa monnieri (L.) Pennell were investigated.